I just got my X3 few days ago from the dealer. It came with the y-cable (I dont have tech package or nav or mobile office). When I attach an iphone 4 or an ipod, x3's idrive recognizes the device and starts the playback. However after 30 seconds to a minute (this duration seems random) idrive loses connection shows no usb connected. Waiting more the system re-recognizes the device just to loose the again.

Has anybody seen this happen? Did the dealer gave me a wrong Y-cable (I dont know if there are different versions), or am doing something wrong?

I have the same issue and it has nothing to do with the Y cable. You should get the vehicle back to the dealer. I've had wiring harnesses replaced and I'm currently waiting on a new radio head unit. I had the issue from the day I picked it up early April. It's so new, trouble shooting is tough and parts were in short supply as they were being channeled to new X3's. Not a big deal for me as I have Sirius.

I think that's only true if you have the tech package. You still need a Y cable if you don't This has been covered at length here

I read through that thread, and it didn't really seem to converge on a solid conclusion. Let me tell you what I know.

Some BMWs past March 2010 production and all BMWs past sept/oct 2010 production can be 6VC "combox" equipped. Among other things, that allows recent model iPods and iPhones pass audio over USB. Older iPods do indeed still require a y-cable, but newer devices do not.

As long as the X3 has 6VC, it can use the Apple cable to transfer music on iPhones and an iPods. As far as I know, all X3 models should have this option, but it may be that it's only X3s with certain other options. It doesn't necessarily have to be the tech package. There are some individual options (ex, BMW Assist including Mobile Office and Bluetooth audio functionality) that use combox.

My 2011 Z4, built in November 2010, has 6VC standard and works with the Apple cable on my iPhone 3GS and 4. The car does not have i-drive or nav, only the "iPod/USB" option (which happens to be standard on the X3).

Bottom line, look for 6VC on your spec sheet. Cars with that code no longer need the Y-cable for iPhones and recent iPods.

That Combox option doesn't come with the cheapest Bluetooth option (in the UK at least) so a Y-Cable is needed. I have the standard X3 hifi with cheapest bluetooth option and need a Y-Cable. Works fine, never had the disconnect problem.

I tried the y cable from my prev 08 328 vert to rule it out, unfortunately as Uppie said it is not the Y cable. I tried the apple cable and this one only charges the device, I dont think I have any tech related items (no BMW assist button ...etc) for this to work

I also tried playing mp3s from a usb stick and interestingly works without a problem. This makes me think perhaps it is a power issue, since iphone needs more juice than the usb stick. I was monitoring the device and it always showed that it was charging. Also since the memory stick is fine I dont think this is a harness issue at least in the comm lines. Perhaps weak 5V or GND. (x3 was parked btw)

I also found the part no 61122167663 from bmw that can take extra juice from the 12 V in the arm rest. Planning to bring the x3 to the dealer tomorrow and if they have this part I will ask them to try it and see if it resolves the issue.

Once I had extended the y-cable by 1 metre so I can screen mount my iPhone it failed to charge quite often and charged very slowly when it did succeed, but it never disconnected from the data/music. I just used some decent brand new USB and Audio extension cables.

To resolve this I bought the following cable and used a standard 12V USB charger in that socket in the armrest to give extra juice for the iPhone.

Phone now charges reliably and works fine with the Y-Cable and extensions. It's still much slower than a mains charger but manages to keep the phone charging a little bit even when running TomTom.

Dealer says they ordered a new radio unit from Germany (like Uppie said) no ETA yet but estimated two weeks... Hopefully it will solve the problem...
On top of this driving home a rock chipped the window... Grrr

This happened to my '09 328 and my new X3 (also without nav). Both times I just asked the dealership for a new Y cable and it fixed the problem. These cables are cheap crap. I now carry a spare in the glovebox.

I tried the y cable from my prev 08 328 vert to rule it out, unfortunately as Uppie said it is not the Y cable. I tried the apple cable and this one only charges the device, I dont think I have any tech related items (no BMW assist button ...etc) for this to work

I also tried playing mp3s from a usb stick and interestingly works without a problem. This makes me think perhaps it is a power issue, since iphone needs more juice than the usb stick. I was monitoring the device and it always showed that it was charging. Also since the memory stick is fine I dont think this is a harness issue at least in the comm lines. Perhaps weak 5V or GND. (x3 was parked btw)

I also found the part no 61122167663 from bmw that can take extra juice from the 12 V in the arm rest. Planning to bring the x3 to the dealer tomorrow and if they have this part I will ask them to try it and see if it resolves the issue.

Uppie what is the lead time to get a new head radio unit?

I just learnt that the radio head unit should be here 6/22 (approx 3 weeks lead time). I'll let you know if it fixes the issue